tanks 4ft long with a cross bar along the rim in the middle going from the front to the back of the tank to prevent the tank from bowing. If I light the tank with 2 individual 4ft catalina HO one plant grow and one 6500k sitting right on top of the tank, will this be enough light to prevent a shaowed effect? Or will the shadow be even more noticeable. the lights would sit right on top. thanks